Initial import

1 files changed, 495 insertions, 0 deletions

diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
new file mode 100644
index 000000000..79ddd580d
--- /dev/null
+++ b/arch/s390/mm/cmm.c
@@ -0,0 +1,495 @@
+/*
+ *  Collaborative memory management interface.
+ *
+ *    Copyright IBM Corp 2003, 2010
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/gfp.h>
+#include <linux/sched.h>
+#include <linux/sysctl.h>
+#include <linux/ctype.h>
+#include <linux/swap.h>
+#include <linux/kthread.h>
+#include <linux/oom.h>
+#include <linux/suspend.h>
+#include <linux/uaccess.h>
+
+#include <asm/pgalloc.h>
+#include <asm/diag.h>
+
+#ifdef CONFIG_CMM_IUCV
+static char *cmm_default_sender = "VMRMSVM";
+#endif
+static char *sender;
+module_param(sender, charp, 0400);
+MODULE_PARM_DESC(sender,
+		 "Guest name that may send SMSG messages (default VMRMSVM)");
+
+#include "../../../drivers/s390/net/smsgiucv.h"
+
+#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
+
+struct cmm_page_array {
+	struct cmm_page_array *next;
+	unsigned long index;
+	unsigned long pages[CMM_NR_PAGES];
+};
+
+static long cmm_pages;
+static long cmm_timed_pages;
+static volatile long cmm_pages_target;
+static volatile long cmm_timed_pages_target;
+static long cmm_timeout_pages;
+static long cmm_timeout_seconds;
+static int cmm_suspended;
+
+static struct cmm_page_array *cmm_page_list;
+static struct cmm_page_array *cmm_timed_page_list;
+static DEFINE_SPINLOCK(cmm_lock);
+
+static struct task_struct *cmm_thread_ptr;
+static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
+static DEFINE_TIMER(cmm_timer, NULL, 0, 0);
+
+static void cmm_timer_fn(unsigned long);
+static void cmm_set_timer(void);
+
+static long cmm_alloc_pages(long nr, long *counter,
+			    struct cmm_page_array **list)
+{
+	struct cmm_page_array *pa, *npa;
+	unsigned long addr;
+
+	while (nr) {
+		addr = __get_free_page(GFP_NOIO);
+		if (!addr)
+			break;
+		spin_lock(&cmm_lock);
+		pa = *list;
+		if (!pa || pa->index >= CMM_NR_PAGES) {
+			/* Need a new page for the page list. */
+			spin_unlock(&cmm_lock);
+			npa = (struct cmm_page_array *)
+				__get_free_page(GFP_NOIO);
+			if (!npa) {
+				free_page(addr);
+				break;
+			}
+			spin_lock(&cmm_lock);
+			pa = *list;
+			if (!pa || pa->index >= CMM_NR_PAGES) {
+				npa->next = pa;
+				npa->index = 0;
+				pa = npa;
+				*list = pa;
+			} else
+				free_page((unsigned long) npa);
+		}
+		diag10_range(addr >> PAGE_SHIFT, 1);
+		pa->pages[pa->index++] = addr;
+		(*counter)++;
+		spin_unlock(&cmm_lock);
+		nr--;
+	}
+	return nr;
+}
+
+static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
+{
+	struct cmm_page_array *pa;
+	unsigned long addr;
+
+	spin_lock(&cmm_lock);
+	pa = *list;
+	while (nr) {
+		if (!pa || pa->index <= 0)
+			break;
+		addr = pa->pages[--pa->index];
+		if (pa->index == 0) {
+			pa = pa->next;
+			free_page((unsigned long) *list);
+			*list = pa;
+		}
+		free_page(addr);
+		(*counter)--;
+		nr--;
+	}
+	spin_unlock(&cmm_lock);
+	return nr;
+}
+
+static int cmm_oom_notify(struct notifier_block *self,
+			  unsigned long dummy, void *parm)
+{
+	unsigned long *freed = parm;
+	long nr = 256;
+
+	nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
+	if (nr > 0)
+		nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
+	cmm_pages_target = cmm_pages;
+	cmm_timed_pages_target = cmm_timed_pages;
+	*freed += 256 - nr;
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cmm_oom_nb = {
+	.notifier_call = cmm_oom_notify,
+};
+
+static int cmm_thread(void *dummy)
+{
+	int rc;
+
+	while (1) {
+		rc = wait_event_interruptible(cmm_thread_wait,
+			(!cmm_suspended && (cmm_pages != cmm_pages_target ||
+			 cmm_timed_pages != cmm_timed_pages_target)) ||
+			 kthread_should_stop());
+		if (kthread_should_stop() || rc == -ERESTARTSYS) {
+			cmm_pages_target = cmm_pages;
+			cmm_timed_pages_target = cmm_timed_pages;
+			break;
+		}
+		if (cmm_pages_target > cmm_pages) {
+			if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
+				cmm_pages_target = cmm_pages;
+		} else if (cmm_pages_target < cmm_pages) {
+			cmm_free_pages(1, &cmm_pages, &cmm_page_list);
+		}
+		if (cmm_timed_pages_target > cmm_timed_pages) {
+			if (cmm_alloc_pages(1, &cmm_timed_pages,
+					   &cmm_timed_page_list))
+				cmm_timed_pages_target = cmm_timed_pages;
+		} else if (cmm_timed_pages_target < cmm_timed_pages) {
+			cmm_free_pages(1, &cmm_timed_pages,
+				       &cmm_timed_page_list);
+		}
+		if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
+			cmm_set_timer();
+	}
+	return 0;
+}
+
+static void cmm_kick_thread(void)
+{
+	wake_up(&cmm_thread_wait);
+}
+
+static void cmm_set_timer(void)
+{
+	if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
+		if (timer_pending(&cmm_timer))
+			del_timer(&cmm_timer);
+		return;
+	}
+	if (timer_pending(&cmm_timer)) {
+		if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
+			return;
+	}
+	cmm_timer.function = cmm_timer_fn;
+	cmm_timer.data = 0;
+	cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
+	add_timer(&cmm_timer);
+}
+
+static void cmm_timer_fn(unsigned long ignored)
+{
+	long nr;
+
+	nr = cmm_timed_pages_target - cmm_timeout_pages;
+	if (nr < 0)
+		cmm_timed_pages_target = 0;
+	else
+		cmm_timed_pages_target = nr;
+	cmm_kick_thread();
+	cmm_set_timer();
+}
+
+static void cmm_set_pages(long nr)
+{
+	cmm_pages_target = nr;
+	cmm_kick_thread();
+}
+
+static long cmm_get_pages(void)
+{
+	return cmm_pages;
+}
+
+static void cmm_add_timed_pages(long nr)
+{
+	cmm_timed_pages_target += nr;
+	cmm_kick_thread();
+}
+
+static long cmm_get_timed_pages(void)
+{
+	return cmm_timed_pages;
+}
+
+static void cmm_set_timeout(long nr, long seconds)
+{
+	cmm_timeout_pages = nr;
+	cmm_timeout_seconds = seconds;
+	cmm_set_timer();
+}
+
+static int cmm_skip_blanks(char *cp, char **endp)
+{
+	char *str;
+
+	for (str = cp; *str == ' ' || *str == '\t'; str++)
+		;
+	*endp = str;
+	return str != cp;
+}
+
+static struct ctl_table cmm_table[];
+
+static int cmm_pages_handler(struct ctl_table *ctl, int write,
+			     void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	char buf[16], *p;
+	unsigned int len;
+	long nr;
+
+	if (!*lenp || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	if (write) {
+		len = *lenp;
+		if (copy_from_user(buf, buffer,
+				   len > sizeof(buf) ? sizeof(buf) : len))
+			return -EFAULT;
+		buf[sizeof(buf) - 1] = '\0';
+		cmm_skip_blanks(buf, &p);
+		nr = simple_strtoul(p, &p, 0);
+		if (ctl == &cmm_table[0])
+			cmm_set_pages(nr);
+		else
+			cmm_add_timed_pages(nr);
+	} else {
+		if (ctl == &cmm_table[0])
+			nr = cmm_get_pages();
+		else
+			nr = cmm_get_timed_pages();
+		len = sprintf(buf, "%ld\n", nr);
+		if (len > *lenp)
+			len = *lenp;
+		if (copy_to_user(buffer, buf, len))
+			return -EFAULT;
+	}
+	*lenp = len;
+	*ppos += len;
+	return 0;
+}
+
+static int cmm_timeout_handler(struct ctl_table *ctl, int write,
+			       void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	char buf[64], *p;
+	long nr, seconds;
+	unsigned int len;
+
+	if (!*lenp || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	if (write) {
+		len = *lenp;
+		if (copy_from_user(buf, buffer,
+				   len > sizeof(buf) ? sizeof(buf) : len))
+			return -EFAULT;
+		buf[sizeof(buf) - 1] = '\0';
+		cmm_skip_blanks(buf, &p);
+		nr = simple_strtoul(p, &p, 0);
+		cmm_skip_blanks(p, &p);
+		seconds = simple_strtoul(p, &p, 0);
+		cmm_set_timeout(nr, seconds);
+	} else {
+		len = sprintf(buf, "%ld %ld\n",
+			      cmm_timeout_pages, cmm_timeout_seconds);
+		if (len > *lenp)
+			len = *lenp;
+		if (copy_to_user(buffer, buf, len))
+			return -EFAULT;
+	}
+	*lenp = len;
+	*ppos += len;
+	return 0;
+}
+
+static struct ctl_table cmm_table[] = {
+	{
+		.procname	= "cmm_pages",
+		.mode		= 0644,
+		.proc_handler	= cmm_pages_handler,
+	},
+	{
+		.procname	= "cmm_timed_pages",
+		.mode		= 0644,
+		.proc_handler	= cmm_pages_handler,
+	},
+	{
+		.procname	= "cmm_timeout",
+		.mode		= 0644,
+		.proc_handler	= cmm_timeout_handler,
+	},
+	{ }
+};
+
+static struct ctl_table cmm_dir_table[] = {
+	{
+		.procname	= "vm",
+		.maxlen		= 0,
+		.mode		= 0555,
+		.child		= cmm_table,
+	},
+	{ }
+};
+
+#ifdef CONFIG_CMM_IUCV
+#define SMSG_PREFIX "CMM"
+static void cmm_smsg_target(const char *from, char *msg)
+{
+	long nr, seconds;
+
+	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
+		return;
+	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
+		return;
+	if (strncmp(msg, "SHRINK", 6) == 0) {
+		if (!cmm_skip_blanks(msg + 6, &msg))
+			return;
+		nr = simple_strtoul(msg, &msg, 0);
+		cmm_skip_blanks(msg, &msg);
+		if (*msg == '\0')
+			cmm_set_pages(nr);
+	} else if (strncmp(msg, "RELEASE", 7) == 0) {
+		if (!cmm_skip_blanks(msg + 7, &msg))
+			return;
+		nr = simple_strtoul(msg, &msg, 0);
+		cmm_skip_blanks(msg, &msg);
+		if (*msg == '\0')
+			cmm_add_timed_pages(nr);
+	} else if (strncmp(msg, "REUSE", 5) == 0) {
+		if (!cmm_skip_blanks(msg + 5, &msg))
+			return;
+		nr = simple_strtoul(msg, &msg, 0);
+		if (!cmm_skip_blanks(msg, &msg))
+			return;
+		seconds = simple_strtoul(msg, &msg, 0);
+		cmm_skip_blanks(msg, &msg);
+		if (*msg == '\0')
+			cmm_set_timeout(nr, seconds);
+	}
+}
+#endif
+
+static struct ctl_table_header *cmm_sysctl_header;
+
+static int cmm_suspend(void)
+{
+	cmm_suspended = 1;
+	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
+	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
+	return 0;
+}
+
+static int cmm_resume(void)
+{
+	cmm_suspended = 0;
+	cmm_kick_thread();
+	return 0;
+}
+
+static int cmm_power_event(struct notifier_block *this,
+			   unsigned long event, void *ptr)
+{
+	switch (event) {
+	case PM_POST_HIBERNATION:
+		return cmm_resume();
+	case PM_HIBERNATION_PREPARE:
+		return cmm_suspend();
+	default:
+		return NOTIFY_DONE;
+	}
+}
+
+static struct notifier_block cmm_power_notifier = {
+	.notifier_call = cmm_power_event,
+};
+
+static int __init cmm_init(void)
+{
+	int rc = -ENOMEM;
+
+	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
+	if (!cmm_sysctl_header)
+		goto out_sysctl;
+#ifdef CONFIG_CMM_IUCV
+	/* convert sender to uppercase characters */
+	if (sender) {
+		int len = strlen(sender);
+		while (len--)
+			sender[len] = toupper(sender[len]);
+	} else {
+		sender = cmm_default_sender;
+	}
+
+	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
+	if (rc < 0)
+		goto out_smsg;
+#endif
+	rc = register_oom_notifier(&cmm_oom_nb);
+	if (rc < 0)
+		goto out_oom_notify;
+	rc = register_pm_notifier(&cmm_power_notifier);
+	if (rc)
+		goto out_pm;
+	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
+	if (!IS_ERR(cmm_thread_ptr))
+		return 0;
+
+	rc = PTR_ERR(cmm_thread_ptr);
+	unregister_pm_notifier(&cmm_power_notifier);
+out_pm:
+	unregister_oom_notifier(&cmm_oom_nb);
+out_oom_notify:
+#ifdef CONFIG_CMM_IUCV
+	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
+out_smsg:
+#endif
+	unregister_sysctl_table(cmm_sysctl_header);
+out_sysctl:
+	del_timer_sync(&cmm_timer);
+	return rc;
+}
+module_init(cmm_init);
+
+static void __exit cmm_exit(void)
+{
+	unregister_sysctl_table(cmm_sysctl_header);
+#ifdef CONFIG_CMM_IUCV
+	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
+#endif
+	unregister_pm_notifier(&cmm_power_notifier);
+	unregister_oom_notifier(&cmm_oom_nb);
+	kthread_stop(cmm_thread_ptr);
+	del_timer_sync(&cmm_timer);
+	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
+	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
+}
+module_exit(cmm_exit);
+
+MODULE_LICENSE("GPL");